In a wireless communications network, user equipment (UE) transmits data on a resource allocated to the user equipment by a base station. The base station determines, according to received channel state information (CSI) obtained by means of measurement by the UE, whether the UE receives interference, and schedules another resource for UE that receives interference by using a resource scheduling method.
There are many types of interference to the UE. If the UE receives interference from an uplink signal of other UE in the network, the UE that receives interference normally receives interference only on some frequency bands or some time-frequency resources regardless of whether the UE that causes interference belongs to the same operator and system as the UE that receives interference or does not belong to the same operator or system as the UE that receives interference.
Currently, there are mainly three CSI measurement reporting methods, as described below.
A first method is a wideband CSI solution. That is, UE reports an average channel state of an entire frequency band. When the UE receives interference from an uplink signal of other UE, it is possible that channel quality of only some frequency bands or some time-frequency resources is relatively poor, but channel quality of other frequency bands is relatively good. Therefore, the average channel state of the entire frequency band cannot reflect actual channel states of frequency bands or time-frequency resources that receive interference.
A second method is an optimal M-subband CSI solution. That is, UE reports channel states of M subbands with optional channel conditions. However, because channel quality of frequency bands or time-frequency resources that receive interference is relatively poor, the channel states of the M subbands with optional channel conditions do not include channel states of these subbands with relatively poor channel quality. Therefore, this solution cannot reflect actual channel states of the frequency bands or time-frequency resources that receive interference, either.
A third method is a subband CSI solution. That is, UE reports a channel state of each subband of an entire frequency band. Although this solution can reflect actual channel states of frequency bands or time-frequency resources that receive interference, a relatively large quantity of resources need to be occupied to report the channel state of each subband of the entire frequency band, and a base station needs to deliver control signaling to trigger reporting of the UE.
In conclusion, how to more accurately and effectively report whether UE receives interference from other UE is to be urgently resolved in the wireless communications network.